The 10 most common canine skin tumors are hemangiosarcomas, histiocytomas, melanocytomas, mast cell tumors, lipomas, hemangiopericytomas, papillomas, fibrosarcomas, hemangiomas, and squamous cell carcinomas. There are 10 types of non-cancerous tumors including sebaceous hyperplasia, fibroepithelial polyps, collagenous hamartomas, infundibular cysts, fibroadnexal hamartomas, scrotal vascular hamartomas, isthmus cysts, sebaceous hamartomas, dermoid cysts, and fibropruritic nodules.
Acrochordons, also called skin tags, soft fibromas, fibroepithelial polyps, fibroma pendulans, pedunculated fibromas, and soft warts, are tumor-like lesions of the skin that occur both in humans and animals. Sometimes they become numerous, closely located growths forming a plaque, predominantly located at the neck. An acrochordon is usually skin colored or of darker color, and it may appear as surface nodules or papillomas on healthy skin. Most acrochordons vary in size from 2-5 mm in diameter, although larger acrochordons up to 5 cm in diameter are sometimes seen. The most frequent localizations are the neck and the armpits, but any skin fold, including the groin, may be affected.3
Although the exact cause of these lesions remains unclear, hormone imbalances have been suggested to facilitate their development. In addition, there is a predisposition in bulldog-like breeds.1 On rare occasions, fibroepithelial polyps can undergo malignant transformation into basal or squamous cell carcinoma. If fibroepithelial polyps occur in the urinary tract, animals may develop urinary incontinence, urinary tract infection, and/or increased thirst and abnormally frequent urination.2
- Bidaut AP, Gross TL, Noli C, Welle M, Suter MM. Acrochordonous plaques in two Bulldogs and a Pug dog. Vet Dermatol. 2003 Jun;14(3):177-9.
- Reichle JK, Peterson RA 2nd, Mahaffey MB, Schelling CG, Barthez PY. Ureteral fibroepithelial polyps in four dogs.Vet Radiol Ultrasound. 2003 Jul-Aug;44(4):433-7.
- Robert A Schwartz, MD, MPH. Acrochordon, emedicine.com, May 30, 2007
- Neoplastic and Nonneoplastic Cutaneous Tumors of Dogs in Grenada, West Indies